I downloaded Sketchup alongwith Openstudio 1.5.3 more than a month ago. Now I am not able to use SketchUp because 1 month free trial has expired. I do not understand this. Do we need to Buy SketchUp if we need to use it with OpenStudio, or has NREL procured a Key for Sketchup which I do not know about. Previous Versions of SketchUp worked for more than a month and I was never Asked to Buy an Product.